cc: Split Proxy to eliminate unnecessary dependencies on the impl side

cc/layers/video_layer_impl.cc

Index: cc/layers/video_layer_impl.cc
diff --git a/cc/layers/video_layer_impl.cc b/cc/layers/video_layer_impl.cc
index d6aa570d11332c77e2669da82b02bfa6e9b099c3..6df7c65c49fa8990ad18f14c3e49516cf65fdc0c 100644
--- a/cc/layers/video_layer_impl.cc
+++ b/cc/layers/video_layer_impl.cc
@@ -15,7 +15,7 @@
 #include "cc/resources/single_release_callback_impl.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "cc/trees/occlusion.h"
-#include "cc/trees/proxy.h"
+#include "cc/trees/thread_verifier.h"
 #include "media/base/video_frame.h"
 
 #if defined(VIDEO_HOLE)
@@ -30,8 +30,8 @@ scoped_ptr<VideoLayerImpl> VideoLayerImpl::Create(
     int id,
     VideoFrameProvider* provider,
     media::VideoRotation video_rotation) {
-  DCHECK(tree_impl->proxy()->IsMainThreadBlocked());
-  DCHECK(tree_impl->proxy()->IsImplThread());
+  DCHECK(tree_impl->thread_verifier()->IsMainThreadBlocked());
+  DCHECK(tree_impl->thread_verifier()->IsImplThread());
 
   scoped_refptr<VideoFrameProviderClientImpl> provider_client_impl =
       VideoFrameProviderClientImpl::Create(
@@ -59,8 +59,8 @@ VideoLayerImpl::~VideoLayerImpl() {
     // on the VideoFrameProviderClientImpl, but we stop when the first
     // LayerImpl (the one on the pending tree) is destroyed since we know
     // the main thread is blocked for this commit.
-    DCHECK(layer_tree_impl()->proxy()->IsImplThread());
-    DCHECK(layer_tree_impl()->proxy()->IsMainThreadBlocked());
+    DCHECK(layer_tree_impl()->thread_verifier()->IsImplThread());
+    DCHECK(layer_tree_impl()->thread_verifier()->IsMainThreadBlocked());
     provider_client_impl_->Stop();
   }
 }